The FBI Thursday briefed the families of the 12 men and woman killed inside the Washington Navy Yard and provided them with Navy officers for additional assistance, News4's Mark Segraves reported.

Meanwhile, some employees returning to work at the Washington Navy Yard Thursday said they felt it was too early to talk about the massacre earlier this week while others said it will take a while to put what happened behind them.

News4's Megan McGrath described the mood as somber as workers stood in line to enter the facility.

'It's traumatic, and it's heartbreaking. I looked at the pictures on TV, and I saw one of the ladies that I, you know, you see around base and the cafeteria," said Portia Hernandez, a returning employee.

Dramatic Photos: DC Navy Yard Shooting

“I'd rather not be here today,” said Judy Farmer, a scheduler from Manassas, Va., one of those who returned to the red bricks of the Navy Yard for the first time since 12 people were gunned down Monday by a shooter who was killed by law enforcement.

The Navy installation re-opened at 6 a.m. for normal operations except the building where the shooting took place.

Bob Flynn, who hid in an office in Building 197 with four colleagues during the shooting, said it helped to be at work with them.

“I feel good because I got to see my co-workers that I went through this with,” Flynn said. “I get to hug people, and everybody gets the hugs and we get to talk about it and I think it's going to be helpful.”

Flynn said Secretary of the Navy Ray Mabus met with them Thursday morning.

“He said, `If anybody has a problem, you call me,' and he means it, and it's just one big family and that's why we're going to be able to make it,” Flynn said.

Flynn recalled hiding with the lights out in a third-floor office, where one colleague called 911, another used a smart phone from under a desk so the light wouldn't be visible and another put chairs against the door as 34-year-old Aaron Alexis fired in the building. Authorities say he was the lone shooter.

“It seemed like it lasted forever as we were hearing gunshots and not knowing what was going on,” Flynn said. “When they finally rescued us later, I had to walk over the body of a very dear friend of mine and, you know, that's hard to get out of my head.”

Brooke Roberts, an engineer who works across the street from the building where the shooting happened, said returning was a bit surreal.

“You don't think this sort of thing can happen to you at your workplace, so you're just not prepared for it, regardless,” he said of the shooting as he walked by a blocked off gate he is accustomed to using to enter the Navy Yard. He described himself as feeling “still unsettled,” noting the blocked off entrance.

“It's still not quite normal, and it probably won't be for some time,” Roberts said.

Barbara Smith said she was feeling apprehensive, walking toward the entrance.

“But, you know, I have to work, and I'm trusting that they're taking care of what needs to be taken care of,” she said.

Navy spokeswoman Lt. Cmdr. Sarah Flaherty said Thursday will be a regular work day, except for Building 197, where the shootings occurred, and the base gym. She says the gym is being used as a staging area for the FBI to investigate Monday's rampage.

The Sixth Street gate remains closed, but employees can expect to be able to enter through the Ninth Street and O Street gates, commanding officer Capt. Monte Ulmer said. Security forces continue to operate as normal. The Ninth Street gate is open 24 hours, and O Street is open from 5:30 a.m. to 5 p.m.

Riverwalk turnstiles will remain closed, and all other gates are secured for law enforcement activities.

Garage 28 may be partially restricted but all other parking garages and lots will be open

As for services at Navy Yard, all food service, Navy Exchange and Navy Federal Credit Union have authorization to reopen, but employees may want to bring their own meals.

Naval District Washington set up an Emergency Family Assistance Center at Navy Yard to assist families and individuals with disaster relief assistance and support, the latest information from leadership, and contingency services. It’s located at the Navy Installations Command headquarters on the fifth floor of Building 111.

It’s the second EFAC established since Monday’s tragedy. The other is in Building 72 at Joint Base Anacostia-Bolling.

The Navy created a family support center to assist personnel or family members affected by the shootings. Call 1-855-677-1755. Family members also can log into NAVY Accountability and Assessment System to muster and fill out a needs assessment and a fleet and family support center emergency case manager will call and offer assistance.